iOS 5 doesn’t bring native support for apps on the Apple TV, but it does introduce AirPlay Mirroring for the iPad 2. Mirroring is a feature that was introduced alongside the iPad 2. It allowed users to display exactly what was on their tablet on an external display, too, using the Digital AV Adapter Apple released that provides an HDMI connection for video and audio out. When it was announced, I said the mirroring ability was the iPad 2’s killer feature. That’s even more true now that Apple has promised to make the technology wireless.

I’ve had a chance to go hands-on with AirPlay Mirroring, and it works as advertised. Once you select your Apple TV as an output source in the multitasking menu bar, everything you do on your iPad will be transmitted to your Apple TV–connected display. Even in this early beta form, it works remarkably well, with very little lag time and without any interruptions in the connection during my test. It does seem to be fairly taxing on the iPad’s battery, but by no means to such an extent that it affects the usefulness of the experience.

It does require that users have both an iPad 2 and an Apple TV in order to work, however. The cost of the Digital AV Adapter from Apple’s retail store is $39, but the Apple TV is itself only $99. That’s still just shy of $100, and even basic wireless video transmitters that don’t provide any additional functionality start at around $80.

Note also that while the home screen and most apps display in the 4:3 aspect ratio of the iPad 2’s screen (or in 3:4 when viewing in portrait orientation), full-screen video outputted to the AirPlay-connected TV automatically adjusts to fill the screen if it is formatted for widescreen. Developers can also specifically tell their apps to adjust to a widescreen aspect ratio, as Firemint has done with Real Racing 2 HD, which it has announced will support HD wireless output in iOS 5.

iCloud may be hogging the tech press spotlight, but AirPlay is Apple’s big play in the living room, and it’s one of the most significant and potentially disruptive new technologies the company has introduced in a long time. iOS 4.3 brought third-party developers access to AirPlay video streaming, a major step in attracting consumer attention to the tech. Now, with AirPlay mirroring, Apple will completely change the way users and the market think about its Apple TV relaunch. With the help of Apple TV, the iPad 2, and future Apple mobile devices that support it, AirPlay Mirroring could become the Google TV that actually works for consumers, and one that users can easily take with them.